Pipeline reinforcement assembly and method

ABSTRACT

An assembly and a method for reinforcing or repairing one or more segments of an existing pipeline, without taking the pipeline out of service and without the need for disassembling the existing pipeline segments that are to be repaired. The assembly incorporates a metallic reinforcement pipe, a front seal ring, a rear seal ring, a front seal ring retention assembly, a rear seal ring retention assembly, and a self-hardening medium receiver. The reinforcement pipe and the seal rings create an annular space between the respective ends of the reinforcement pipe and the external surface of the existing pipeline. The seal rings, seal ring retention assemblies, and the flexible reinforcement pipe, accommodate out-of-round and joint angular displacement conditions of the existing pipeline. A self-hardening medium is injected into the annular space and pressure is maintained on the medium until the medium has set.

PRIOR RELATED APPLICATION

This application is a continuation-in-part of application Ser. No.13/290,022 filed by applicant on Nov. 4, 2011.

FIELD OF THE INVENTION

This invention is in the field of devices and methods for pipereinforcement and repair and, in particular, in the field of devices andmethods for externally structurally reinforcing or repairing segments ofexisting pipelines while retaining the existing pipelines in place and,if needed, in service.

BACKGROUND OF THE INVENTION

Many pipelines currently in operation have become structurally deficientdue to corrosion, erosion or other causes which damage the structuralintegrity of the pipeline. Some structural deficiencies may have beencaused by defects in the original design, defects in the manufacturingprocess, incorrect installation, or the effects of corrosion due to age.These structural deficiencies may be intermittent or continuous innature. In addition, some pipeline systems have increased operatingdemands and would benefit from an increase in the allowable pressure ofthe existing pipe and the corresponding flow capacity increase.

The operators of these pipelines are frequently dependent on thepipelines and are unable to discontinue use without severe consequences.Often it is not economically feasible to replace the system, such aswhen the deficiencies are intermittent in nature or when the pipelinecannot be taken out of service.

Whether the pipelines are transmitting water or some other fluid, thepassage of time results in increased incidents of leakage and increasingconcerns over the structural integrity of the pipeline. In somesituations, a new pipeline can and will be constructed to replace theexisting pipeline. The new pipeline will be placed in service and theold pipeline removed or simply abandoned. In many situations, however,the replacement of the pipeline is economically or functionallyinfeasible. The cost may be prohibitive. Constructing a parallelpipeline may be difficult or impossible and retaining the existingpipeline in service may be essential. Thus, in many situations, a systemand method for reinforcing or repairing an existing pipeline whileretaining the pipeline in service is seriously needed.

A number of systems and methods have been developed for repairingpipeline segments in place, such as the system and method disclosed inU.S. Pat. No. 7,165,579 to Borland, et al. Each of the prior art systemsand methods have provided a technically feasible system or method formaking a repair to the existing pipeline, and have done so with varyingdegrees of success. Many of the pipelines needing reinforcement orrepair are large diameter, exceeding 12 feet in diameter, and haveinconsistent external dimensions or have external mortar coatings. Priorart systems are not easily adaptable to these pipe sizes or externalsurface irregularities. Prior art systems utilize and require rigidenclosures to assure that a gasket maintains intimate contact with theexisting pipeline and the enclosure so as to provide that the system issealed. Some prior art systems are connected to the existing pipeline insuch a way as to render them inflexible.

Prior art disclosures include systems utilizing half-shell enclosureswherein bolts are utilized to rigidly center the half shells around theexisting pipeline and gaskets combined with hardware provide end sealsto allow injecting resin at high pressure into the annular void. Such asystem is limited to use with existing pipe having very accurate anduniform pipe dimensions and gasket seats for such a system require arigid cylinder for the enclosure in order for the gasket to seal duringpressurization. Further, a gasket seal system does not provide aneffective means to seal against a concrete or mortar coated pipeline. Incontrast the current invention provides a flexible enclosure withpassive centering means, including end seals which allow the enclosureto be rounded upon pressurization. Unlike many other prior art devices,the seal rings and the seal retainers of the current invention do notinterfere with joining multiple overlapping enclosures to provide alengthened sealed enclosure system. Embodiments of the enclosure of thepresent invention allow maintaining a seal against an irregular surfacesuch as concrete or mortar coated pipelines. When combining theenclosure system of the present invention with the pipeline supportsystem of the present invention, the work space requirements such as theexcavation for a buried pipeline will be minimized. This support systemalso provides the means to continue with multiple enclosures whilesupporting the existing pipeline or enclosure.

Other prior art disclosures include repair systems which include customfabricated shapes intended for a specific localized repair and do notprovide for adjustments necessary for irregularities in the existingpipeline. Also, they are intended for localized repair and do notprovide for interconnecting enclosures to create a continuous andextendable repair. For these systems, rounding of the cylinder isprohibited as the geometry of the fabricated shape causes the cylinderto become rigid. Bolted embodiments of these systems require a rigidstructure in order for the bolted assembly to retain its shape andseals. A tapping tool is utilized to pierce the existing pipeline andpressurize the annular space within the enclosure. Such systems seemwell suited for repair of petroleum pipelines with uniform externaldimensions.

Other prior art systems provide a clamp style repair device and utilizea liquid sealant. These systems require a rigid structure which isfurther complicated by the need to heat the device before installing toassure a shrink to fit assembly will seal the device edges. Thesedevices are intended for a localized repair and for use with existingpipelines with uniform existing pipe dimensions to work properly. Theprotruding hardware of these systems makes the use of coatings forcorrosion protection very difficult and indicates the system is onlyintended for localized repairs.

It is an objective of the present invention to provide a system andmethod for pipeline reinforcement which is more economical, both as tomaterials and labor, easier and faster to install, and more reliablethan the prior art systems and methods.

It is a further objective of the present invention to provide a pipelinereinforcement system and method that provides for the readyreinforcement of contiguous segments of pipeline.

It is a further objective of the present invention to provide a pipelinereinforcement system and method that provides for the readyreinforcement of contiguous segments of pipeline; provides for thetemporary suspension of pipeline reinforcement construction, leaving thereinforced sections in a structurally sound condition; and provides forthe resumption of pipeline reinforcement construction for sectionscontiguous to sections completed prior to the suspension at a later datewithout the need for modification to the system.

It is a further objective of the present invention to provide a systemand method for repairing stretches of pipeline involving multiplepipeline segments with a continuous external pipe enclosure.

It is a further objective of the present invention to provide a pipelinereinforcement system and method which provides a round and cylindricalreinforcement pipe, for each section of existing pipe reinforced,regardless of whether the existing pipeline is round or out-of-round.

It is a further objective of the present invention to provide a systemand method for pipeline reinforcement that uses a “flexible” pipe designfor a pipe enclosure. The meaning of the term “flexible” as applied toreinforcement pipe sections for purposes of this application is providedhereafter.

SUMMARY OF THE INVENTION

Although the present invention is deployable with rigid enclosure pipe,the present invention offers the distinct advantage over prior artdevices and methods because it is particularly adapted for use with“flexible” reinforcement pipe, which is defined hereafter in thisapplication.

A preferred embodiment of the pipe reinforcement assembly of the presentinvention has a reinforcement pipe top, a reinforcement pipe bottom, afront seal ring and a rear seal ring. Although a preferred embodiment ofthe enclosure of the present invention, namely the reinforcement pipe,has two laterally arcuate enclosure plates, the reinforcement pipe topand the reinforcement pipe bottom, the reinforcement pipe mayincorporate more than two laterally arcuate enclosure plates. Theenclosure plates have an internal surface with a common and uniformlateral radius of curvature, the radius of curvature being greater thanthe existing pipe external radius. The enclosure plates are fittedtogether longitudinally to form a flexible, cylindrical enclosure forthe existing pipeline segment being reinforced.

In a preferred method of the present invention, the existing pipelinemay be supported by existing pipeline supports of the present invention,the reinforcement pipe bottom is then fed beneath the existing pipelineand positioned with the radial center line approximately beneath theexisting pipe joint. Reinforcement pipe supports of the presentinvention may be used to position the reinforcement pipe bottomimmediately beneath the existing pipeline with the reinforcement pipebottom internal surface separated from the existing pipe externalsurface by a desired clearance. Clearance spacers may be pre-attached tothe internal surface of the reinforcement pipe bottom so that when thereinforcement pipe bottom is positioned beneath the existing pipelineand supported by the reinforcement pipe supports, the internal surfaceof the reinforcement pipe bottom is separated from the external surfaceof the existing pipeline by the desired reinforcement pipe clearance.

The reinforcement pipe top is then positioned over the existing pipelinewith the reinforcement pipe top longitudinal edges mating with thereinforcement pipe bottom longitudinal edges, and the reinforcement pipetop front radial edge being longitudinally matched with thereinforcement pipe bottom front radial edge, and the reinforcement pipetop rear radial edge being longitudinally aligned with the reinforcementpipe bottom rear radial edge. The existing pipeline external radius andthe reinforcement pipe internal radius providing for the desiredclearance.

For a preferred embodiment, the reinforcement top longitudinal edges maybe welded to the reinforcement bottom longitudinal edges. Althoughwelding is a preferred methodology for joining the reinforcement pipetop to the reinforcement pipe bottom, other means will be known topersons skilled in the art, such as mechanical joints.

For a preferred embodiment shown, the reinforcement pipe top and thereinforcement pipe bottom have an expanded pipe end at the respectiverear radial edges. This provides for the joining of successivereinforcement pipes assemblies, thereby providing for a continuousreinforcement pipe for a pipeline segment including multiple segments ofthe existing pipeline.

After the reinforcement pipe top and the reinforcement pipe bottom havebeen appropriately positioned with a pipeline clearance between theinternal surfaces respectively of the reinforcement pipe top and thereinforcement pipe bottom, and the pipeline external surface, and thelongitudinal edges of the reinforcement pipe top and a reinforcementpipe bottom have been welded, or otherwise permanently connected to formthe longitudinal joints, thereby forming reinforcement pipe, the frontseal ring and the rear seal ring are installed. In a preferredembodiment the seal rings are made of a flexible, resilient,compressible material and hence each would preferably be made in onepiece with the ends brought together as the front seal ring is insertedat the reinforcement pipe front end in the front edge annular spacebetween the reinforcement pipe and the existing pipe and the rear sealring is inserted at the reinforcement pipe rear end in the rear edgeannular space between the reinforcement pipe and the existing pipeline.

In a preferred embodiment of the method of the present invention, theinjection of self-hardening medium, into the annular space between theexisting pipe and the reinforcement pipe, is accomplished through amedium receiver at a pressure that is sufficient, when the annular spaceis completely filled, to overcome gravitational and other forces on thereinforcement pipe and to force the reinforcement pipe to a truecircular cross-section and a true cylindrical shape. In a preferredembodiment of the method of the present invention, a pressure ismaintained that is sufficient to preserve the circular cross-section andtrue cylindrical shape until the self-hardening medium has hardened.

The inventor prefers to use an expanding grout as the medium because itexpands during curing, rather than shrinking as many grouts do. The endresult of this preferred embodiment of the method of the presentinvention is a true cylindrical reinforcement pipe which carries orreinforces the pressure capacity of the existing pipeline and evenlydisburses the hoop stress and the other loads imposed on thereinforcement pipe by the existing pipeline. As stated above, theexpanding grout can result in the pre-stressing of the reinforcementpipe, immediately transferring loads to the reinforcement pipe. This canbe particularly important in the reinforcement of an existing pipe whichis experiencing a failure or deterioration of its hoop stress structuralcapacity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective, exploded view of a pipe reinforcementassembly of a preferred embodiment of the present invention.

FIG. 2 is a front perspective view of a pipe reinforcement assembly of apreferred embodiment of the present invention.

FIG. 3 a is a front perspective view detail of a reinforcement pipebottom of the present invention without clearance spacers.

FIG. 3 b is a front perspective view detail of a reinforcement pipebottom of the present invention with clearance spacers.

FIG. 4 is a vertical longitudinal cross-section of a reinforcement pipeof the present invention installed on an existing pipeline,approximately centered on the joint between two existing pipe sections.

FIG. 5A is a cross section detail for a preferred embodiment of a frontseal ring as inserted to a reinforcement pipe of the present inventionin a front edge annular space between the reinforcement pipe internalsurface and the existing pipeline external surface.

FIG. 5B is a cross section detail of a preferred embodiment of a sealring retention assembly of the present invention which incorporates aclamping retainer to retain the seal ring.

FIG. 5C is a cross section detail of a preferred embodiment of a sealring retention assembly of the present invention which incorporates ashrinkable sleeve and a clamping retainer to retain the seal ring.

FIG. 5D is a cross section detail of a preferred embodiment of a sealring retention assembly of the present invention which incorporates ashrinkable sleeve seal with an integral seal retainer.

FIG. 5E is a cross section detail of an alternative embodiment of a sealring of the present invention with a concave inside surface and aclamping retainer.

FIG. 6A is a cross section detail of an alternative embodiment of theseal ring and the seal ring retention assembly of the present invention.

FIG. 6B is a cross section detail of an alternative embodiment of theseal ring and the seal ring retention assembly of the present invention.

FIG. 6C is a cross section detail of an alternative embodiment of theseal ring and the seal ring retention assembly of the present inventionwhich may be used with a reinforcement pipe of the present inventionhaving a contracted reinforcement pipe front end.

FIG. 6D is a cross section detail of an alternative embodiment of theseal ring and the seal ring retention assembly of the present inventionwhich may be used with a reinforcement pipe of the present inventionhaving a contracted reinforcement pipe front end.

FIG. 6E is a cross section detail of an alternative embodiment of theseal ring and the seal ring retention assembly of the present inventionwherein a bowed reinforcement pipe front end and an oversized seal ringprovide for the retention and positioning of the seal ring.

FIG. 6F is a cross section detail of an alternative embodiment of theseal ring and the seal ring retention assembly of the present inventionwhich incorporates a shrink sleeve.

FIG. 7 is a vertical longitudinal cross section of an existing pipelinewith a continuous reinforcement pipe of the present inventionreinforcing two or more existing pipe sections.

FIG. 8A is a cross section detail of a preferred embodiment of areinforcement pipe first termination joint assembly.

FIG. 8B is a cross section detail of a preferred embodiment of areinforcement pipe continuation joint assembly.

FIG. 8C is a cross section detail of a preferred embodiment of areinforcement pipe first termination joint assembly.

FIG. 9 is a vertical longitudinal cross section of an existing pipelinewith a continuous reinforcement pipe of the present inventionreinforcing two or more existing pipe sections.

FIG. 10A is a cross section detail of a preferred embodiment of areinforcement pipe first termination joint assembly.

FIG. 10B is a cross section detail of a preferred embodiment of areinforcement pipe continuation joint assembly.

FIG. 10C is a cross section detail of a preferred embodiment of areinforcement pipe first termination joint assembly.

FIG. 11 is a front perspective view of a preferred embodiment of asupport system of the present invention with support wedge assemblies.

FIG. 12 is a cross-section of an embodiment of the reinforcement pipe ofthe present invention installed on an existing pipe section with spacersproviding the desired pipeline clearance.

FIG. 13A is a cross section detail of a preferred embodiment of aclearance spacer installed between the existing pipe external surfaceand the reinforcement pipe internal surface.

FIG. 13B is a cross section detail of a preferred embodiment of aclearance spacer installed between the existing pipe external surfaceand the reinforcement pipe internal surface.

FIG. 13C is a cross section detail of a preferred embodiment of aclearance spacer installed between the existing pipe external surfaceand the reinforcement pipe internal surface.

FIG. 13D is a cross section detail of a preferred embodiment of aclearance spacer installed between the existing pipe external surfaceand the reinforcement pipe internal surface.

FIG. 14 is an illustration of a preferred embodiment of a mediumreceiver, medium supply assembly, and vent assembly of the presentinvention.

FIG. 15 is an illustration detail of a preferred embodiment of a mediumreceiver and medium supply assembly of the present invention.

FIG. 16 is a vertical longitudinal cross-section of a reinforcement pipeof the present invention installed on an existing pipeline, illustratingalso the positioning of a preferred embodiment of a seal ring and sealring retention assembly of the present invention.

FIG. 17 is a front perspective view detail of a preferred embodiment ofa seal ring of the present having one seal ring segment with taperedends and illustrating overlapping of the tapered ends of the seal ringsegment.

FIG. 18 is a cross section detail of a preferred embodiment of a sealring and seal ring retention assembly of the present inventionillustrating the seal ring of FIG. 17 and a clamping retainer to retainthe seal ring.

FIG. 19 is a cross section detail of a preferred embodiment of the sealring of the present invention illustrated in FIG. 17, illustratingoverlapping of the segment ends of the seal ring segment.

FIG. 20A is top view of a preferred embodiment of a seal ring segment ofthe seal ring of FIG. 17.

FIG. 20B is a cross section detail of a preferred embodiment of a sealring segment of the seal ring of FIG. 17.

FIG. 20C is a cross section detail of a preferred embodiment of a sealring segment of the seal ring of FIG. 17, illustrating a fluid supplyvalve for the seal ring segment.

FIG. 20D is a cross section detail of a preferred embodiment of a sealring segment of the seal ring of FIG. 17, illustrating the tubular,inflatable portion and tapered segment end of the seal ring segment.

FIG. 21 is a front perspective view detail of a preferred embodiment ofa seal ring of the present having two seal ring segments with taperedends and illustrating overlapping of the tapered ends of the seal ringsegments.

FIG. 22 is a front perspective view detail of a seal ring retainerassembly incorporating a seal retainer consisting of a seal retainerring having two retainer ring segments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As noted above, although the present invention is deployable with rigidenclosure pipe, the present invention offers the distinct advantage overprior art devices and methods because it is particularly adapted for usewith “flexible” reinforcement pipe, i.e. “flexible” enclosure pipe.According to a commonly used criteria, “rigid” pipe is defined as pipewhich will not allow deflections beyond 0.1% ( 1/10%) of the pipediameter without damage to the structural integrity of the pipe.“Semi-rigid” pipe will generally not allow deflections beyond 2% of thepipe diameter without damage to the structural integrity of the pipe.According to commonly used criteria, a “flexible” pipe will allowdeflections beyond 2% of the pipe diameter without damage to thestructural integrity of the pipe. The deflections of a flexible conduitare generally thought to be limited to less than 20% of the conduitdiameter but do not have a defined limitation. As stated, a distinctadvantage of the pipe reinforcement assembly and method of the presentinvention is that it is adaptable to use and is intended for use withflexible reinforcement pipe. For this application, including the claims,the term “flexible”, when used with the term “pipe”, “reinforcementpipe”, “reinforcement pipe top”, “reinforcement pipe bottom”, or“enclosure plate” shall be defined to mean a pipe, reinforcement pipe,reinforcement pipe top, reinforcement pipe bottom, or enclosure platethat allows deflections beyond the limits stated above for “rigid” andbeyond the limits stated above for “semi-rigid” pipe.

Referring first to FIG. 1, a front view, perspective, exploded view ofthe pipe reinforcement assembly 1 of a preferred embodiment of thepresent invention is shown. In this illustration, two sections of anexisting pipeline 3, a first pipe section 5 and a second pipe section 7,the pipe sections being connected at existing pipe joint 9. For theembodiment shown, portions of the first pipe section 5 and the secondpipe section 7

The embodiment of the pipe reinforcement assembly 1 of the presentinvention shown in FIG. 1 has a reinforcement pipe top 13, areinforcement pipe bottom 15, a front seal ring 17 and a rear seal ring19. For the embodiment shown, the reinforcement pipe length 43 for thereinforcement pipe top 13 and the reinforcement pipe bottom 15 isapproximately equal to the existing pipe section length 45. For otherembodiments, however, the reinforcement pipe length 43 may differ fromthe existing pipe section length 45, and may be greater than or lessthan the existing pipe section length 45.

Referring also to FIG. 2, although a preferred embodiment of theenclosure 2 of the present invention, namely the reinforcement pipe 71,has two laterally arcuate enclosure plates 4, namely a reinforcementpipe top 13 and a reinforcement pipe bottom 15 as shown in FIG. 1 andFIG. 2, the reinforcement pipe 71 may incorporate more than twolaterally arcuate enclosure plates 4, each of the enclosure plateshaving an internal surface with a common and uniform lateral radius ofcurvature 65, the radius of curvature being greater than the existingpipe external radius 67, the enclosure plates being fitted togetherlongitudinally to form a flexible, cylindrical enclosure 2 for thepipeline segment, the enclosure, namely the reinforcement pipe 71,having an internal surface and opposing ends, a first enclosure end anda second enclosure end, which, for the preferred embodiment shown inFIG. 1 and FIG. 2, are the reinforcement pipe front end 75 and thereinforcement pipe rear end 77. For purposes of this application, theterms “longitudinal” and “longitudinally” shall be defined to meangenerally longitudinal with respect to the centerline of the existingpipeline, but not necessarily exactly parallel to the centerline of theexisting pipeline. For the embodiment shown, the existing pipe segmentwhich is reinforced by the reinforcement pipe 71 includes portions ofthe first pipe section 5 and the second pipe section 7, including theexisting pipe joint 9 between the two sections.

In a preferred method of the present invention, utilizing the embodimentof the reinforcement pipe assembly 1 shown in FIG. 1, the existingpipeline 3 may be supported by existing pipeline supports 39. Thereinforcement pipe bottom 15 is then fed beneath the existing pipelineand positioned with the radial center line 47 approximately beneath theexisting pipe joint 9. Reinforcement pipe supports 41 may be used toposition the reinforcement pipe bottom immediately beneath the existingpipeline with the reinforcement pipe bottom internal surface 51separated from the existing pipe external surface 53 by a desiredclearance 59 as shown on FIG. 2. Referring also to FIG. 3B, as shown inFIG. 1, for an alternative embodiment, clearance spacers 37 may bepre-attached to the internal surface 51 of the reinforcement pipe bottom15, the radial thickness of the clearance spacers 37 being equal to thedesired clearance 59, so that when the reinforcement pipe bottom ispositioned beneath the existing pipeline and supported by thereinforcement pipe supports 41, the internal surface 51 of thereinforcement pipe bottom is separated from the external surface 53 ofthe existing pipeline by the desired reinforcement pipe clearance 59.Alternatively, the spacers may be secured to the existing pipeline or noclearance spacers 37 may be used for the reinforcement pipe bottom 15 asshown in FIG. 3A.

The reinforcement pipe top 13 is then positioned over the existingpipeline with the reinforcement pipe top longitudinal edges 31 matingwith the reinforcement pipe bottom longitudinal edges 33, and thereinforcement pipe top front radial edge 21 being longitudinally matchedwith the reinforcement pipe bottom front radial edge 23, and thereinforcement pipe top rear radial edge 25 being longitudinally alignedwith the reinforcement pipe bottom rear radial edge 27 as shown in FIG.2. The existing pipeline external diameter 57 and hence the existingpipeline external radius 67 and the reinforcement pipe internal diameter55 and hence the reinforcement pipe internal radius 65 providing for thedesired clearance 59 as shown in FIG. 2.

For a preferred embodiment, the reinforcement top longitudinal edges 31may be welded to the reinforcement bottom longitudinal edges 33. For theembodiment shown in FIG. 1, the reinforcement bottom longitudinal edgeshave an edge backing 35 which assists in the positioning of thereinforcement pipe top on the reinforcement pipe bottom and in thesubsequent welding of the reinforcement pipe top to the reinforcementpipe bottom. Although welding is a preferred methodology for joining thereinforcement pipe top to the reinforcement pipe bottom, other meanswill be known to persons skilled in the art, such as mechanical joints.

For the embodiment shown, the reinforcement pipe top 13 and thereinforcement pipe bottom 15 have an expanded pipe end 29 at therespective rear radial edges 25, 27. This provides for the joining ofsuccessive reinforcement pipes assemblies 1, thereby providing for acontinuous reinforcement pipe for multiple segments of the existingpipeline 3.

Referring again to FIG. 2, after the reinforcement pipe top 13 and thereinforcement pipe bottom 15 have been appropriately positioned with apipeline clearance 59 between the internal surfaces respectively 51 and61 of the reinforcement pipe top and the reinforcement pipe bottom, andthe pipeline external surface 53, and the longitudinal edges of thereinforcement pipe top and a reinforcement pipe bottom have been welded,or otherwise permanently connected to form the longitudinal joints 73,thereby forming reinforcement pipe 71, the front seal ring 17 and therear seal ring 19 are installed. In a preferred embodiment the sealrings 17, 19, are made of a flexible, resilient, compressible materialand hence each would preferably be made in one piece with the endsbrought together as the front seal ring 17 is inserted at thereinforcement pipe front end 75 of the reinforcement pipe 71 in thefront edge annular space 81 between the reinforcement pipe 71 and theexisting pipe 3 and the rear seal ring 19 is inserted at thereinforcement pipe rear end 77 and the rear edge annular space 83between the reinforcement pipe 71 and the existing pipeline 3.

Referring to FIG. 4, a vertical longitudinal cross-section of areinforcement pipe 71 as installed on an existing pipeline,approximately centered on the joint between two existing pipe sectionsis shown. Referring also to FIG. 5A, a cross section detail is shown fora preferred embodiment of a front seal ring 17 as inserted to thereinforcement pipe 71 in the front edge annular space 81 between thereinforcement pipe internal surface 51, 61, and the existing pipelineexternal surface 53. FIGS. 5B, 5C and 5D show several preferredembodiments of seal ring retention assemblies 93 which retain the sealring 17 in the position shown in FIG. 5A, as a time hardening materialis injected in the annular space 85 and pressurized as described below.FIG. 5B illustrates the use of a clamping retainer 87 to retain the sealring 17. FIG. 5C illustrates the use of a shrinkable sleeve seal 89,which typically has an adhesive backing to provide for a positive sealbetween the existing pipe 3 and the shrinkable sleeve seal 89, and aclamping retainer 87. FIG. 5D illustrates the use of a shrinkable sleeveseal with an integral seal retainer 91. FIG. 5E illustrates the use ofan alternative embodiment of a seal ring 17, with a concave insidesurface 111 to enhance the sealing capability of the seal ring, and aclamping retainer 87.

Referring now to FIG. 6A-6D, details of additional alternativeembodiments of the seal ring 17 and the seal ring retention assembly 93are shown. FIG. 6A illustrates the use of a seal ring that is largerthan the front edge annular space 81 between the reinforcement pipefront end 75 and the existing pipeline external surface 53 and is heldadjacent to the reinforcement pipe front end 75 by an expanded clampingretainer 95. Referring to FIG. 6B, an embodiment of the seal ring 17 andthe seal ring retention assembly 93 is shown that is similar to thatshown in FIG. 6A except that a shrinkable sleeve seal 89 has been added.As noted above, the shrinkable sleeve seals 89 are typically installedwith adhesive backing. Referring now to FIG. 6C, an embodiment of theseal ring is shown which may be used with a reinforcement pipe 71 with acontracted reinforcement pipe front end 99. FIG. 6D illustrates a sealring and seal retainer assembly similar to that shown in FIG. 6C with ashrinkable sleeve seal 89 added. FIG. 6E illustrates a seal ring andseal retainer assembly wherein a bowed reinforcement pipe front end 113and an oversized seal ring 17 provide for the retention and positioningof the seal ring 17. For this embodiment, a contiguous reinforcementpipe 201 has a contiguous reinforcement pipe rear end 203 with a rearend receiver surface 205 which mates with a front end receiver surface115 of the reinforcement pipe 71 and allows the reinforcement pipe frontend 75 to be welded or otherwise joined to the contiguous reinforcementpipe rear end 203 thereby forming a continuous reinforcement pipe 207.FIG. 6F illustrates the use of a shrink sleeve 117 affixed to theexisting pipe external surface 53 and the reinforcement pipe 71respectively by a pair of clamping retainers 87, to retain the real ring17 and seal the reinforcement pipe front end 75.

Other seal ring retention assemblies 93 for retaining the seal ring 17in place in the annular space 81, 83 will be obvious to a person ofordinary skill in the art, in view of the drawings and descriptionspresented in this application.

Referring again to FIG. 5A and FIG. 6A, for example, a preferred type ofseal ring 17 comprises a flexible tubular member 18, such as a neoprenetube, with an internal fluid chamber 20 which can be injected with andpressurized with a seal fluid, such as a liquid or air, to expand theseal ring 17 to fill the front edge annular space 81 and the rear edgeannular space 83 respectively. The seal ring material will generally besupplied on a roll and cut to the proper length in the field at the timeof installation. A field splice is required to join the ends of sealring and to attach and imbed a seal ring manifold for use in injectingthe seal fluid. The utilization of a liquid or non-compressible sealfluid is preferred because it will allow rounding of the enclosure, i.e.the reinforcement pipe, without loss of the seal. Some embodiments ofthe seal ring retention assembly 93 of the current inventionincorporates a mastic coated shrink sleeve 89 under the seal ring 17 tosmooth surface irregularities such as found on concrete or mortar coatedpipelines. Other embodiments of the seal ring utilize a pliant geometricshaped seal which deforms, under pressure, to occupy and seal theannular space between the enclosure ends and the existing pipe. Otherembodiments of the seal ring utilize a shaped pliant compressiblematerial such as a gasket which is removably attached against the endsof the enclosure and retained by use of metal hardware segments whichare secured in position with a tensioned cable. Upon completing theinjection and hardening of the medium, the securing cables are releasedand the previously secured seals are removed in preparation forcontiguous enclosures or a termination of the system.

Also, if it is desired that the self-hardening medium be injecteddirectly to the annular space at the front pipe end or the rear pipeend, or both, without the use of a medium receiver in the reinforcementpipe itself, the seal ring may have a medium receiver which is aninjection penetration passing through and imbedded in the seal ring.

Referring now to FIG. 7, a vertical longitudinal cross section of anexisting pipeline 3 with a continuous reinforcement pipe 207 reinforcingtwo or more existing pipe sections is illustrated. Referring also toFIGS. 8A, 8B and 8C, preferred embodiments of a reinforcement pipe firsttermination joint 119 assembly, a reinforcement pipe continuation jointassembly 121, and a reinforcement pipe second termination joint assembly123, respectively are shown for this type of existing pipeline. Thesedetails illustrate the termination of a continuous reinforcement pipe207 and a preferred embodiment of a termination assembly for attachingthe ends of the continuous reinforcement pipe to this type of existingpipeline by welding a termination member 101 to the existing pipe.

Referring now to FIG. 9, a vertical longitudinal cross section of anexisting pipeline 3 with a continuous reinforcement pipe 207 reinforcingtwo or more existing pipe sections is illustrated. Referring also toFIGS. 10A, 10B and 10C, preferred embodiments of a reinforcement pipefirst termination joint 119 assembly, a reinforcement pipe continuationjoint assembly 121, and a reinforcement pipe second termination jointassembly 123, respectively are shown for this type of existing pipeline.These details illustrate the termination of a continuous reinforcementpipe 207 and a preferred embodiment of a termination assembly forattaching the ends of the continuous reinforcement pipe to this type ofexisting pipeline by attaching a termination member 107 to the existingpipeline by a termination shrink sleeve 109.

Referring now to FIG. 12, a cross-section of an embodiment of thereinforcement pipe 71 of the present invention installed on an existingpipe section 3, with spacers 133 providing the desired pipelineclearance 59 between the existing pipe external surface 53 and thereinforcement pipe internal surface 51, 61. Referring also to FIGS.13A-13D, cross-section details of embodiments with spacers 133 areshown. Utilization of spacers aids in the installation of thereinforcement pipe bottom 15 and the reinforcement pipe top 13, butparticularly the reinforcement pipe bottom 15, and help minimize damageto the reinforcement pipe bottom or top during placement, positioningand installation. Spacers may be used for the reinforcement pipe bottom,the reinforcement pipe top, both the reinforcement pipe bottom and thereinforcement pipe top, or neither.

Referring now to FIG. 14 and to FIG. 15, a medium receiver 135 of thepresent invention for use in injecting the self-hardening medium isshown. For the embodiment of the reinforcement pipe 71 shown, the mediumreceiver 135 is merely a threaded opening located at or near theenclosure bottom 137. A corresponding medium vent 139 is located at ornear the enclosure top 141. For the embodiment shown, the medium vent139 is also merely a threaded opening in the reinforcement pipe 71. Asthe self-hardening medium is injected 171 into the annular space 85, airis expelled 173 from the annular space 85 through the medium vent 139.Depending on the diameter and length of the reinforcement pipe 71, thepipeline clearance 59, the type of hardening medium, the existingpipeline material, and the reinforcement pipe material, as well as otherfactors, more than one medium receiver 135 may be used for areinforcement pipe 71. Likewise, more than one medium vent 139 may beused.

An embodiment of a medium supply assembly 143 consisting of a mediumpump 145, supply piping 147, valves 149, and a pressure gauge 151,provides for the supply, pressurization and injection of theself-hardening medium 153, 171, and for the supply, pressurization anddischarge of pump flushing fluid 155, 157. An embodiment of a ventassembly 159 consisting of vent piping 161, valves 163, and a pressuregauge 165, provide for the venting of air 173 from the annular space 85,and, once all the air has been expelled from the annular space 85, thenfor the containment of the self-hardening medium. The medium supplyassembly 143 and the vent assembly 159 shown are merely illustrative asother embodiments for supplying, pressurizing, and injecting theself-hardening medium, and for venting air and flushing pumps and pipeswill be known to persons of ordinary skill in the art. Other embodimentsof the medium receiver 135, other than the threaded opening shown, forattaching a source of self-hardening medium to the reinforcement pipe,will be known to persons skilled in the art. Similarly, otherembodiments of the medium vent 139, other than the threaded openingshown, for attaching the reinforcement pipe to a device for venting airfrom the reinforcement pipe and containing pressurized medium, will beknown to persons skilled in the art. Alternative embodiments of themedium receiver 135 may provide for direct injection of theself-hardening medium into the annular space 85, by a medium receiverwhich penetrates and is imbedded in the seal ring.

The type of self-hardening medium material preferred by the inventor isa low viscosity, expanding grout made from finely milled constituents.The low viscosity and small particle size of the constituents providefor the medium to readily distribute and completely fill the annularspace 85 between the existing pipeline 3 and the reinforcement pipe 71connecting the front edge annular space 81 and the rear edge annularspace 83. The hardened medium will be of an adequate density to transferthe stresses of the pipeline to the reinforcement pipe. Expansion of themedium as it cures provides for uniform bearing and load transferbetween the existing pipeline and the reinforcement pipe. Expansion ofthe medium as it cures pre-stresses the reinforcement pipe, furtherinsuring the “roundness” and hence the true cylindrical nature of thereinforcement pipe. This provides for the ready connection of successivereinforcement pipes for the reinforcement of contiguous segments of anexisting pipeline.

In a preferred embodiment of the method of the present invention, theinjection of self-hardening medium into the annular space 85 through themedium receiver 135 is accomplished at a pressure that is sufficient,when the annular space is completely filled, to overcome gravitationaland other forces on the reinforcement pipe 71 and to force thereinforcement pipe to a true circular cross-section and a truecylindrical shape. In a preferred embodiment of the method of thepresent invention, a pressure is maintained that is sufficient topreserve the circular cross-section and true cylindrical shape until theself-hardening medium has hardened. As indicated above, the inventorprefers to use an expanding grout as the medium because it expandsduring curing, rather than shrinking as many grouts do. The end resultof this preferred embodiment of the method of the present invention is atrue cylindrical reinforcement pipe which carries or reinforces thepressure capacity of the existing pipeline and evenly disburses the hoopstress and the other loads imposed on the reinforcement pipe by theexisting pipeline. As stated above, the expanding grout can result inthe pre-stressing of the reinforcement pipe, immediately transferringloads to the reinforcement pipe. This can be particularly important inthe reinforcement of an existing pipe which is experiencing a failure ordeterioration of its hoop stress structural capacity.

If passive centering spacers are used, the spacers will partially yieldto the forces of the pressurized annular medium and allow rounding ofthe enclosure. The intimate contact caused by the annular medium willact to transfer the stresses from the existing pipeline to the newrounded reinforcement pipe enclosure. If the existing pipeline is in theprocess of structural failure or in need of supplemental structuralstrength, this reinforcement will act to replace the deficient existingpipeline structural strength and allow continued operation of theexisting pipeline.

The rounding of the reinforcement pipe, as described above, assures thatthe existing pipeline stresses are transferred symmetrically to thereinforcement pipe. This substantially improves the strength of thereinforcement pipe by equalizing the stresses throughout thereinforcement pipe enclosure and optimizes the structural strength ofthe reinforcement pipe. Thin wall fabricated metallic cylinders areknown to be flexible, and roundness must be provided by other means. Forthe method of the present invention, rounding is provided by sealingboth ends of each enclosure segment between the enclosure and theexisting pipeline adequately to allow pressurizing the annular spacewith a self hardening medium. As stated, the use of a pressurized,expansive medium will act to pre-stress the metallic cylinder. Personsof skill in the art familiar with liquid containing pressurizedcylindrical structures will readily recognize that the result ofpressurizing a flexible metallic cylinder is to cause the cylinder tobecome substantially round. For the reinforcement pipe of the presentinvention, this will occur irrespective of the roundness or soundness ofthe existing pipeline. Unless the enclosure, the reinforcement pipe, isrounded at the time of installation, the stresses of the existing pipewill not be transferred equally and could cause concentrated stresses tothe enclosure which in turn could cause the structural failure of theenclosure. The use of a flexible enclosure combined with roundingminimizes the required thickness of the enclosure thereby minimizing theexpense of the system. By contrast, a rigid enclosure without suchrounding would require substantially increased material thicknesses toachieve the equivalent strength.

Important and unique features of the assembly and the method of thepresent invention are the use of embodiments of the seal ring 17 and theseal ring retention assembly 93, and the flexible reinforcement pipe 71,to accommodate irregularities in the cross-section of the existingpipeline 3 and accommodate angular displacement in the pipe jointbetween the existing pipe sections. The reinforcement pipe may besubstantially displaced and deformed prior to injection andpressurization of the hardening medium. The flexibility of the sealrings allows rounding of the enclosure while maintaining a seal betweenthe enclosure and the pipeline. Medium pressurization shall be adequateto cause the enclosure to plastically yield into a substantiallycircular shape. The circular shape shall be maintained until the annularmedium has hardened.

Preferred embodiments of this invention are easily adaptable to verylarge diameter pipelines. Many of the pipelines requiring reinforcementor repair exceed 12 feet in diameter and do not have very consistentexternal dimensions or have external mortar coatings resulting in anout-of-round external condition. The preferred embodiments of thisinvention are easily scalable to accommodate very large diameterexisting pipelines. The assembly and method of the present invention canalso accommodate these external dimension variations and externalsurface condition variations for the existing pipeline. The preferredembodiments of the seal ring 17 and the seal ring retention assemblies93 described provide for the reinforcement pipe 71, the seal ring 17,and the seal ring retention assembly 93, to be installed out-of-round.Injection and pressurization of the medium result in rounding of thereinforcement pipe.

The pipe reinforcement assembly 1 and the method of the presentinvention are intended primarily for use in reinforcing a metallic orcementious existing pipeline 3, and primarily for the use of a metallicreinforcement pipe 71. Although most applications will involve the useof steel, steel alloy, or stainless steel, other types of flexiblemetallic pipe may be used, depending on the pipe being reinforced.

A plurality of reinforcement pipes 71 may be connected together toprovide for a continuous reinforcement, reinforcing a pipeline segmentincluding a plurality of contiguous existing pipeline sections. Anexpanded pipe end over a plain end interconnection between successivereinforcement pipes has been shown in the drawings, and is a preferredinterconnection joint, but other types of joints will be known topersons of ordinary skill in the art in view of the disclosures of thisapplication.

The reinforcement pipe ends may be left, temporarily or permanently,terminated in accordance with one of the details shown in the drawings,or an equivalent, or may be terminated by utilizing a shrink sleeve asshown in FIG. 6F, or incorporate a welded connection to the existingpipeline when used with a metal pipeline. These are common methods andmaterials for the pipeline construction industry.

The present invention is intended primarily for use with existingpipelines constructed from Pre-stressed Concrete Cylinder Pipe (PCCP),Reinforced Concrete Pipe (RCP), Ductile Steel, Steel, Cast Iron,Polyvinyl Chloride (PVC), fiberglass reinforced plastics and HighDensity Polyethylene (HDPE) pipe, but may be used with existingpipelines constructed of other materials.

In using the present invention to repair an existing pipeline, such as apipeline constructed of Pre-stressed Concrete Cylinder Pipe, which mayhave lost the hoop component of its structural capacity but may haveretained the compressive strength of the concrete, the user will benefitby preserving and using the compressive strength characteristic of thepipe while replacing the hoop structure of the existing pipe by thereinforcement pipe of the present invention. A seal ring of the presentinvention acts to seal the ends of the annular space between theexisting pipeline and the reinforcement pipe, even for very irregularsurfaces such as those frequently found on pipelines with a concreteexterior. The irregularities are often caused by corrosion, concretespalling due to exposure or age, or lack of quality in manufacturing.

The use of metallic material, such as steel, for the reinforcement pipe,exposes the reinforcement pipe to corrosion. Depending on the materialselected for the self-hardening medium, filling the annular space withthe medium potentially results in the protection of the internal surfaceof the reinforcement pipe from corrosion by passivation of the steel.For example, this can be achieved by utilizing a cementious mediummaterial with a high ph value for a carbon steel reinforcement pipe.This medium material will passivate the steel susceptibility from theeffects of corrosion.

The external surface of the reinforcement pipe can be protected with acorrosion resistant coating, and, due to the smooth finished exteriorwhich is free from accessory hardware, sharp edges, bolts, and the like,the coating system can more easily provide protection of the mostlyuninterrupted shape of the reinforcement pipe external surface.

As shown in FIG. 1, the existing pipeline 3 may be supported by existingpipeline supports 39 of the present invention, and the reinforcementpipe 71 may be supported by reinforcement pipe supports 41 of thepresent invention. Other devices may be used to support the existingpipeline so as to prevent damage to the existing pipeline and toposition and support the reinforcement pipe so as provide for the properpositioning of the reinforcement pipe with respect to the existingpipeline and to support the reinforcement pipe and the existing pipe, asthe reinforcement pipe is constructed, the seal rings and seal retainersare installed, and the medium is injected. The support devices becomeincreasingly valuable when the existing pipeline system is a largediameter and/or the system is buried in the ground.

To facilitate the installation of the enclosure of the presentinvention, the method of the present invention optionally incorporatesthe use of devices to support the existing pipeline while allowingadequate space for installing the enclosure. The support of the existingpipeline during installation of the enclosure, i.e. the reinforcementpipe, which may be operating or contain a liquid such as water, is verycrucial to the use of the assembly and method of the present invention.

As shown in FIG. 1 and FIG. 2, and generally in several of the otherfigures, a preferred embodiment of a support system 38 utilizes one ormore support wedge assemblies 40 comprising a pair of support wedges 39,such as that shown on FIG. 11, which are slid along a steel plate 129 totransfer the dead load of the pipeline to the ground below the pipelinebut outside of the repair zone. This allows the ground within the repairzone to be removed to provide a clearance which facilitates theinstallation of the enclosure 2. This transfer requires careful controlsto assure the pipeline is not shifted or lifted and, therefore, thehydraulics or pneumatic system driving the wedges must have gauges andcalculated lifting rates to assure the optimum pressure is exerted underthe pipeline. The support wedges 39 are preferably mechanicallyinterconnected 131 to provide for the balanced lifting of the existingpipe. Resilient contact surfaces 125, 127 may reduce damage to the pipeas the support wedges are slid under the pipe.

Once the existing pipeline is adequately supported, one or more supportwedge assemblies 40 may also be used to support the enclosure 2, i.e.the reinforcement pipe bottom 15 and the reinforcement pipe top 13,before and after they are joined to form the reinforcement pipe 71, eachof which has a pair of support wedges 41, which are also preferablyhydraulically or pneumatically actuated. Upon completion of anindividual enclosure 2, additional supports may be installed below theenclosure to transfer the pipeline dead load to the enclosure therebyallowing removal of the supports from the existing pipeline andproviding access for a contiguous existing pipeline segment to receivean enclosure. The method of the present invention provides for theenclosure of a pipeline segment including a plurality of contiguousexisting pipeline sections with a continuous, sealed enclosure.

Referring to FIG. 17, a preferred embodiment of a one piece seal ringsegment 301 for use in forming the front seal ring 17 and the rear sealring 19 is shown. Referring also to FIGS. 19, 20A, 20B, and 20D, theseal ring segment 301 is tapered on each end to provide for mating ofthe first segment end 303 and the second segment end 305, as shown inFIG. 17 and FIG. 9, while also providing for seal ring segments 301 tobe fitted in the front edge annular space 81 and the rear edge annularspace 83 respectively. FIG. 19 illustrates the end overlapping 307 ofthe first segment end 303 and the second segment end 305 which providesfor the inflatable, tubular portion 309, with an internal fluid chamber20 as shown in FIG. 20D, of the seal ring segment 301 to have a fluidchamber overlap 311 with the respective non-tubular, non-inflatabletapered segments of the respective segment ends 303, 305. For apreferred embodiment of the method and the pipeline segmentreinforcement assembly of the present invention, the respective ends ofthe tubular portion 309 of the seal ring segment 301 will also overlap,providing for the seal ring to reliably seal the entire annular spacewhen the internal fluid chamber 20 of the tubular portion ispressurized.

This embodiment of the front seal ring 17 and the rear seal ring 19, asformed from the seal ring segment 301 provides a seal for theself-hardening medium without the need for a continuous, circular sealring with no free ends. The ease of installing a seal ring 17, 19constructed of the seal ring segment 301 is greatly improved by beingformed by a seal ring segment with free ends, the first segment end 303and the second segment end 305. The use of such a seal ring segment 301allows for greater variation in the host pipe circumference. Theinflation of each seal ring 17, 19 exerts an equal load on thereinforcement pipe inside surface and the host pipe external surfacewhich tends to evenly distribute the annular space and promote roundingof the reinforcement pipe. In many cases the rounding caused byinflating the front seal ring 17 and the rear seal ring 19 will beadequate to achieve rounding of the reinforcement pipe even beforeintroduction of the self-hardening medium, which provides for more evendistribution of the self-hardening medium. The seal rings may beabandoned in the annular space or may be removably installed. Passivecentering spacers 37 may not be required depending on the pressuresachieved with the seal and roundness of the host pipe.

Referring to FIG. 16, a vertical longitudinal cross-section of areinforcement pipe 71, as installed on an existing pipeline, is shown.Referring also to FIG. 18, a cross section detail is shown for apreferred embodiment of a front seal ring 17 and rear seal ring 19 asinserted to the reinforcement pipe 71 in the front edge annular space 81between the reinforcement pipe internal surface 51, 61, and the existingpipeline external surface 53.

Referring again to FIGS. 17, 20A, 20B, and 20D, a preferred embodimentof a seal ring 17, 19 comprises a flexible seal ring segment 301 withtubular segment 309, such as a neoprene tube, with an internal fluidchamber 20 which can be inflated with and pressurized with anon-compressible or a compressible seal fluid, such as a liquid or air,to expand the seal ring 17 to fill the front edge annular space 81 andthe rear edge annular space 83 respectively. Referring to FIG. 20C, afluid supply valve 313, such as a Schrader® valve, may be used to supplyseal fluid to the internal fluid chamber 20 of the seal ring segment301, after the seal ring segment has been inserted in the annular space.

The seal ring segment 301 will generally be supplied with a length suchthat when it is installed around the host pipe within the annular space,the length will allow the first segment end 303 to overlap the secondsegment end 305, thereby providing for the seal ring 17, 19 to seal theannular space when the internal fluid cavity 20 of the tubular segment309 is pressurized. A field splice is not required to join the ends ofseal ring which allows easy installation and removal subsequent to thegrouting operation. The utilization of a gas or liquid to inflate theseal ring 17, 19 will provide for rounding of the reinforcement pipe,without loss of the seal. The seal ring segments 301 can be manufacturedin single lengths long enough to be utilized on very large pipelinediameters. This embodiment of the seal rings 17, 19 is suitable for mostpipe materials. Other embodiments of the seal rings may also be formedfrom multiple seal ring segments 301 such as shown in FIG. 21 whichillustrates a seal ring 17, 19 comprised of two seal ring segments 301which are overlapped as described above to achieve a completed seal.Other embodiments of the seal ring segments 301 may provide for thefluid chamber 20 to extend into one or both of the tapered segment ends303, 305.

Referring now to FIG. 22, the seal ring retention assembly 93 mayincorporate a seal retainer 86 which comprises a seal retainer ring 88.The seal retainer ring 88 may comprise two or more seal retainer ringsegments 90, each seal retainer ring 88 having a seal retainer ringinside radius 92 equal to or slightly greater than the existing pipeexternal radius 67. A front seal retainer ring 94 may be positionedadjacent to the reinforcement pipe front end 75 and attached to thepipeline segment of the existing pipeline 3 being reinforced or to thereinforcement pipe front end 75. A rear seal retainer ring 96 may bepositioned adjacent to the reinforcement pipe rear end 77 and attachedto the pipeline segment of the existing pipeline 3 being reinforced orto the reinforcement pipe rear end 77.

Other embodiments of the seal ring 17 and seal retention assembly 93which provide for the installation of reinforcement pipe 71,particularly a flexible reinforcement pipe, out of round and with anangular displacement, will be known to persons of ordinary skill in theart, in view of the disclosures made in this application.

Although the preferred embodiments shown in the drawings of thereinforcement pipe assembly 1 of the present invention are for thereinforcement or repair of existing pipeline segments that are straight,i.e. no bend, in view of the drawings and description presented in thisapplication, variations of the assembly and method of the presentinvention for use for mitered bends of an existing pipeline that must bereinforced or repaired, will be obvious to persons of skill in the art.

Other embodiments and other variations and modifications of theembodiments described above will be obvious to a person skilled in theart. Therefore, the foregoing is intended to be merely illustrative ofthe invention and the invention is limited only by the following claimsand the doctrine of equivalents.

What is claimed is:
 1. A method for reinforcing a pipeline segment, themethod providing a capability for reinforcing the pipeline segmentwherein the pipeline segment may have an irregular external surface, maybe out of round or may have an angular displacement, the pipelinesegment having a pipe external surface with a pipe external radius, themethod comprising the steps of: a) enclosing the pipeline segment withtwo or more metallic, laterally arcuate enclosure plates, each of theenclosure plates having an internal surface with a common and uniformlateral radius of curvature, the radius of curvature being greater thanthe pipe external radius, the enclosure plates being fitted togetherlongitudinally to form a flexible, cylindrical enclosure for thepipeline segment, the enclosure having an internal surface and opposingends, a reinforcement pipe front end and a reinforcement pipe rear end;b) installing a pair of seal rings, wherein the pair of seal ringscomprises a front seal ring and a rear seal ring, each seal ring beingcomprised of one or more seal ring segments, the front seal ring beinginserted at the reinforcement pipe front end between the pipe externalsurface and the enclosure internal surface, and the rear seal ring beinginserted at the reinforcement pipe rear end between the pipe externalsurface and the enclosure internal surface, the seal rings promoting anannular space between the pipe external surface and the enclosureinternal surface, each seal ring segment comprising a tubular portionwith an inflatable internal fluid chamber, a first segment end, and asecond segment end, the first segment end and the second segment endeach being tapered to provide for overlapping and mating of the firstsegment end with the second segment end for a seal ring having one sealring segment, or to provide for overlapping and mating of the firstsegment end of the seal ring segment with the second segment end of anadjacent seal ring segment, and providing for forming a continuous sealring; c) installing a pair of seal ring retention assemblies, one sealring retention assembly being installed for each seal ring, the pair ofseal ring retention assemblies comprising a front seal ring retentionassembly and a rear seal ring retention assembly, the front seal ringretention assembly being attached to the pipeline segment or thereinforcement pipe front end and the rear seal ring retention assemblybeing attached to the pipeline segment or the reinforcement pipe rearend; d) injecting a self hardening medium into the annular space throughone or more hardening medium receivers; e) pressurizing theself-hardening medium in the annular space to a rounding pressure, therounding pressure providing for rounding of the flexible cylindricalenclosure and achievement of a true cylindrical shape by the enclosure,self-hardening medium pressurization being adequate to cause theenclosure to plastically yield into a substantially circular shape, eachseal ring and seal retention assembly allowing rounding of the flexibleenclosure and achievement of a true cylindrical shape by the enclosurethough the pipeline segment may have an irregular external surface, maybe out of round or may have an angular displacement; and f) maintainingthe pressure of the self-hardening medium at a pressure equaling orexceeding the rounding pressure until the self-hardening medium hashardened, the true cylindrical shape of the enclosure, irrespective ofsurface irregularities or angular displacement of the pipeline segment,and the hardened medium providing for a transfer of and an evendistribution of all or a substantial portion of hoop stress from thepipeline segment to the enclosure during pressurized use of the pipelinesegment.
 2. The method recited in claim 1 wherein the pair of seal ringretention assemblies comprises a pair of seal retainer rings, whereinthe pair of seal retainer rings comprises a front seal retainer ring anda rear seal retainer ring, each seal retainer ring being comprised oftwo or more retainer ring segments and each seal retainer ring having aninside radius equal to or slightly greater than the pipe externalradius, the front seal retainer ring being positioned adjacent to thereinforcement pipe front end and attached to the pipeline segment or thereinforcement pipe front end, and the rear seal retainer ring beingpositioned adjacent to the reinforcement pipe rear end and attached tothe pipeline segment or the reinforcement pipe rear end.
 3. The methodrecited in claim 1 wherein each hardening medium receiver is integratedwith one of the enclosure plates.
 4. The method recited in claim 1wherein each hardening medium receiver passes through and is embedded inone of the seal rings.
 5. The method recited in claim 1 wherein theenclosure plates comprise a reinforcement pipe top and a reinforcementpipe bottom.
 6. The method recited in claim 1 wherein the enclosureplates are welded together longitudinally.
 7. The method recited inclaim 1 wherein the enclosures plates are joined together longitudinallyin a mechanical joint.
 8. The method recited in claim 1 wherein thereinforcement pipe front end or the reinforcement pipe rear end isexpanded for overlapping the end of a contiguous enclosure, providingfor a continuous enclosure.
 9. The method recited in claim 1 wherein theseal ring has a capability for being injected with and pressurized witha non-compressible fluid.
 10. The method recited in claim 1 wherein eachseal ring comprises a flexible seal ring segment, the seal ring segmentcomprising a tubular portion with an inflatable internal fluid chamber,a first segment end, and a second segment end, the first segment end andthe second segment end each being tapered to provide for overlapping andmating of the first segment end with the second segment end andproviding for forming a continuous seal ring.
 11. The method recited inclaim 1 wherein each seal ring comprises a plurality of flexible sealring segments, each seal ring segment comprising a tubular portion withan inflatable internal fluid chamber, a first segment end, and a secondsegment end, the first segment end and the second segment end each beingtapered to provide for overlapping and mating of the first segment endof the seal ring segment with the second segment end of an adjacent sealring segment to and providing for forming a continuous seal ring.
 12. Amethod for reinforcing a pipeline segment, the pipeline segment having apipe external surface with a pipe external radius, the method comprisingthe steps of: a) enclosing the pipeline segment with a reinforcementpipe top and a reinforcement pipe bottom, the reinforcement pipe top andthe reinforcement pipe bottom being fitted together longitudinally toform a flexible reinforcement pipe, the reinforcement pipe having aninternal surface and opposing ends, a reinforcement pipe front end and areinforcement pipe rear end; b) installing a pair of seal rings, whereinthe pair of seal rings comprises a front seal ring and a rear seal ring,the front seal ring being inserted at the reinforcement pipe front endbetween the pipe external surface and the reinforcement pipe internalsurface, and the rear seal ring being inserted at the reinforcement piperear end between the pipe external surface and the reinforcement pipeinternal surface, the seal rings promoting an annular space between thepipe external surface and the reinforcement pipe internal surface, eachseal ring comprising a flexible seal ring segment, the seal ring segmentcomprising a tubular portion with an inflatable internal fluid chamber,a first segment end, and a second segment end, the first segment end andthe second segment end each being tapered to provide for overlapping andmating of the first segment end with the second segment end andproviding for forming a continuous seal ring; c) installing a pair ofseal ring retention assemblies, one seal ring retention assembly beinginstalled for each seal ring, the pair of seal ring retention assembliescomprising a front seal ring retention assembly and a rear seal ringretention assembly, the front seal ring retention assembly beingattached to the pipeline segment or the reinforcement pipe front end andthe rear seal ring retention assembly being attached to the pipelinesegment or the reinforcement pipe rear end; d) injecting a selfhardening medium into the annular space through one or more hardeningmedium receivers; e) pressurizing the self-hardening medium in theannular space to a rounding pressure, the rounding pressure providingfor rounding of the flexible cylindrical enclosure and achievement of atrue cylindrical shape by the enclosure, self-hardening mediumpressurization being adequate to cause the enclosure to plasticallyyield into a substantially circular shape, each seal ring and sealretention assembly allowing rounding of the flexible enclosure andachievement of a true cylindrical shape by the enclosure though thepipeline segment may have an irregular external surface, may be out ofround or may have an angular displacement; and f) maintaining thepressure of the self-hardening medium at a pressure equaling orexceeding the rounding pressure until the self-hardening medium hashardened, the true cylindrical shape of the enclosure, irrespective ofsurface irregularities or angular displacement of the pipeline segment,and the hardened medium providing for a transfer of and an evendistribution of all or a substantial portion of hoop stress from thepipeline segment to the enclosure during pressurized use of the pipelinesegment.
 13. The method recited in claim 12 wherein the pair of sealring retention assemblies comprises a pair of seal retainer rings,wherein the pair of seal retainer rings comprises a front seal retainerring and a rear seal retainer ring, each seal retainer ring beingcomprised of two or more retainer ring segments and each seal retainerring having an inside radius equal to or slightly greater than the pipeexternal radius, the front seal retainer ring being positioned adjacentto the reinforcement pipe front end and attached to the pipeline segmentor the reinforcement pipe front end, and the rear seal retainer ringbeing positioned adjacent to the reinforcement pipe rear end andattached to the pipeline segment or the reinforcement pipe rear end. 14.The method recited in claim 12 wherein each hardening medium receiver isintegrated with the reinforcement pipe top or the reinforcement pipebottom.
 15. The method recited in claim 12 wherein each hardening mediumreceiver passes through and is embedded in one of the seal rings. 16.The method recited in claim 12 wherein the reinforcement pipe top andthe reinforcement pipe bottom are welded together longitudinally. 17.The method recited in claim 12 wherein the reinforcement pipe top andthe reinforcement pipe bottom are joined together longitudinally in amechanical joint.
 18. The method recited in claim 12 wherein thereinforcement pipe front end or the reinforcement pipe rear end isexpanded for overlapping the end of a contiguous enclosure, providingfor a continuous enclosure.
 19. The method recited in claim 12 whereinthe seal ring has a capability for being injected with and pressurizedwith a non-compressible fluid.
 20. The method recited in claim 12wherein each seal ring comprises a flexible seal ring segment, the sealring segment comprising a tubular portion with an inflatable internalfluid chamber, a first segment end, and a second segment end, the firstsegment end and the second segment end each being tapered to provide foroverlapping and mating of the first segment end with the second segmentend and providing for forming a continuous seal ring.
 21. The methodrecited in claim 12 wherein each seal ring comprises a plurality offlexible seal ring segments, each seal ring segment comprising a tubularportion with an inflatable internal fluid chamber, a first segment end,and a second segment end, the first segment end and the second segmentend each being tapered to provide for overlapping and mating of thefirst segment end of the seal ring segment with the second segment endof an adjacent seal ring segment to and providing for forming acontinuous seal ring.